This invention relates to circuit simulation and particularly to a fast simulation method for single and coupled lossy lines with frequency-dependent parameters based on triangle impulse responses.
Trademarks: S/390, RS/6000 and IBM are registered trademarks of International Business Machines Corporation, Armonk, N.Y., U.S.A. Other names may be trademarks or product names of International Business Machines Corporation, as is G5, or other companies.
There are a lot of transmission lines in a package for a mainframe computer system as discussed by G. Katapis, D. Becker, and H. Stoller, in the article xe2x80x9cFirst level package design considerations for IBM""s S/390 G5 server,xe2x80x9d published in Proc. IEEE 7th Topical Meet. Elect. Performance Electron. Packag., West Point, N.Y., Oct. 1998, pp.15-16. As system clock frequency and integration density increase, the loss of a transmission line in IC package can no longer be neglected. In mainframe computer package design and other high-speed IC package design applications, I have to simulate systems with large number (for example, 100 k) of single and coupled lossy transmission lines. In addition to accuracy, simulation time is another important criterion for a tool. The existing models for lossy transmission lines are, I have found to be, usually too slow to be used directly in such a simulation, especially when frequency-dependent properties such as skin-effect are taken into account. Fast simulation methodology becomes one of the key issues in accurate design of high-speed IC package in mainframe computers.
A fast simulation method is provided for simulating loss in transmission lines for a netlist for an IC package. Based on a triangle impulse response database of lossy transmission lines, this method has a much faster speed than, and a satisfactory accuracy as compared with, existing tools. The new method of calculating uses a triangle impulse response database generated for a test circuit. Then, my new method calculates iteratively, with the use of triangle waveforms represented as time domain basis functions for a netlist for an IC package and also requests for triangle impulse responses from the database of lossy transmission lines, the time domain response of netlist circuit transmission lines with different lengths and different dimensions for the IC package.